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Finding the Fourth Proportional to 425.30, 638.28 and 208.76

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Solution

The fourth proportional to 425.30, 638.28 and 208.76 is: 313.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    425.30 : 638.28 = 208.76 : x
  2. Step 2: Convert to fraction form
    425.30/638.28 = 208.76/x
  3. Step 3: Cross multiply
    425.30x = 638.28 × 208.76
  4. Step 4: Simplify right side
    425.30x = 133,247.33
  5. Step 5: Solve for x
    x = 133,247.33/425.30
  6. Step 6: Final answer
    x = 313.30

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.